PhysicalConstants

Gravitational constant: G = 6.67430(15) × 10⁻¹¹ m³/(kg·s²) Relative uncertainty: 2.2 × 10⁻⁵ One of the least precisely known constants!

Reduced Planck constant: ℏ = h/(2π) (exact, derived from h). In theory, this is exact, but in practice, we can't divide a number by π and still have an exact result. Now, if they had made h-bar exact, we could have made h exact simply by representing it in radians.

Represents the Avogadro constant (N_A), which is the proportionality factor that relates the number of constituent particles (usually atoms or molecules) in a sample to the amount of substance in moles.

Its value is defined as 6.02214076 × 10^23 (exactly), and its unit is the reciprocal of the mole.

Defined as a quantity with the dimensionless unit divided by the mole (Dimensionless / Mole).

Gas constant: R = k·Nₐ Derived from: R = k·Nₐ Exact (product of exact constants)

Rydberg constant: R∞ = 10973731.568160(21) m⁻¹ Relative uncertainty: 1.9 × 10⁻¹²

Fine structure constant: α = 7.2973525693(11) × 10⁻³ (dimensionless) Relative uncertainty: 1.5 × 10⁻¹⁰

NOTE: not to be confused with 1/137 which is 0. the eight digits are recurring.

Represents the speed of light in vacuo, defined as an immutable quantity with a value of 299,792,458 meters per second.

This value is a physical constant used in various scientific calculations, including those related to relativity, electromagnetism, and quantum mechanics.

Defined in the context of the PhysicalConstants class, this quantity is of type Quantity[Velocity], where Velocity is a dimension representing speed.

The unit of measurement is MetersPerSecond, which precisely correlates to the SI standard for velocity.

Represents the elementary charge, a physical constant that quantifies the charge of a single proton or the magnitude of the charge of a single electron.

This constant is expressed as a Quantity with a value of "1.602176634E-19" and is measured in the SI unit of charge, the Coulomb (C).

The elementary charge is a fundamental parameter in physics and is integral to the study of electromagnetism, quantum mechanics, and other physical theories.

Vacuum permittivity: ε₀ = 8.8541878128(13) × 10⁻¹² F/m Derived from: ε₀ = 1/(μ₀c²) Relative uncertainty: 1.5 × 10⁻¹⁰

Represents the Planck constant, a fundamental physical constant used in quantum mechanics. Defined as a measurable quantity with a value of 6.62607015 × 10⁻³⁴ Joule-seconds (J·s).

This constant is expressed as a Quantity with the dimension of energy multiplied by time (EnergyTime). It is utilized in calculations involving energy, frequency, and photon behavior.

The Boltzmann constant, denoted as k, is a physical constant connecting the average kinetic energy of particles in a gas with the temperature of the gas. Its value is exactly 1.380649 × 10⁻²³ J/K.

Electron mass: mₑ = 9.1093837015(28) × 10⁻³¹ kg Relative uncertainty: 3.0 × 10⁻¹⁰

Proton mass: mₚ = 1.67262192369(51) × 10⁻²⁷ kg Relative uncertainty: 3.1 × 10⁻¹⁰

Vacuum permeability: μ₀ = 1.25663706212(19) × 10⁻⁶ H/m Previously exact (4π × 10⁻⁷), now measured Relative uncertainty: 1.5 × 10⁻¹⁰

Stefan-Boltzmann constant: σ = 5.670374419... × 10⁻⁸ W/(m²·K⁴) Derived from: σ = (2π⁵k⁴)/(15h³c²) Exact in SI 2019 (derived from exact constants) NOTE at present our library does not allow us to express π⁵ as an exact number.